Design Your Own Experiment (Day 2)

Objective

Big Idea

Students need opportunities to explore science and develop their own experiments.

Lesson Author

Mariana Garcia Serrato

San Jose, CA

Grade Level

Seventh grade

Subjects

Science

Science Skills

Scientific Method (Science Skills)

experimental design

Standards

Hook

5 minutes

Before the lesson begins, I have collected the materials students need based on the plans they submitted the day before. I have also commented on their plans using the I like-I wish-I wonder protocol taught yesterday.

To start the lesson, I tell students they need to refine their plans based on peer and my feedback. Once they have acted on the feedback, they have to again trade with a different group who will again give feedback. Once they have gone through this process and they have refined their experimental procedure, they transfer it to a piece of chart paper. This signals me that they are ready to perform the experiment, and I give them access to the materials they requested.

I also tell students that they must discuss and agree in advance the roles they are taking during the experiment:

Manager: Person who is in charge of making sure everyone is participating, and that the plan is being followed. This person is also in charge of keeping all controlled variables in check.

Record keeper: Person who is in charge of writing down the data that is being collected. This person is also responsible of taking notes/keeping track of any modifications made to the experimental procedure.

Errand monitor: Person who is in charge of gathering the supplies and request help from the teacher when the group agrees they do not have the resources to solve a problem. If the experiment is timed, this person is also responsible for handling and using the timer.

Experimenters: Persons who are in charge of performing the experiment. Ideally there are two experimenters per group which attempts to get rid of individual variation.

I made name tags of experiment roles, printing them on card stock and using yarn to create loops. This makes the roles "official" to the students since they have to wear them. I use this type of role assignment for group tasks in order to keep students accountable for the job at hand.

Experiment Roles

Experiment Design Planning Sheet

Guided Inquiry

35 minutes

This lesson allows students to get at the root of NGSS Practice 3. The students, on their own, plan and carry out an investigation, identify their variables and controls, decide for themselves which measurements will be recorded, collect data, evaluate their experimental design and propose ideas to improve on their designs.

While the students are refining their plans, I circulate the room making sure the students not only are acting on the feedback, but also have a plan to gather their data. This is an important part of planning and carrying out investigations (Practice 3 Planning and Carrying Out Investigations) that the students often forget in the excitement of experimenting.

Once the students have transferred their experiment plan to the chart paper and begin to perform the experiments, I continue to monitor the groups' progress, checking on how the students are performing the roles they chose/were assigned. This gives me an overview of the group dynamics and gives me some information to use in future group pairings.

It might be stressful to think about "running" all these experiments, within a class period no less, but as you can see in the video, the students manage themselves:

Design your own experiment day 2.mp4

Constructing Explanations

Once the groups are done with their experiments (including any clean-up) and they have their data, I tell them that they will now need to prepare to report their findings to the class. This takes the form of experiment posters, so as a group they must now discuss their results and complete their Experiment Design Planning Sheet. The information added to the planning sheet is used as a first draft of the poster. I also tell students that I will formally evaluate their posters using a lab report rubric and pass out one copy per team.

In order to help with the conclusion, I provide the following guiding questions:

What interpretations and inferences can you draw from your results? (Practice 6 Constructing Explanations and Designing Solutions)

Was your hypothesis supported? Refuted? Is it unclear as to which? Why? (Practice 6)

What is the evidence upon which you make your interpretations? Use specific data from your results. (Practice 7 Engaging in Argument from Evidence)

What variables did you find difficult to control? Why? (Practice 3 Planning and Carrying Out Investigations)

What kinds of modifications did you need to make in your procedure as you tried it? Why? (Practice 7)

The student groups still need to transfer their discussion and conclusions to the poster they will present to the class. It is important to not rush the conclusion process since this is where the students are making sense of their observations and engaging in scientific discussions, so this is tomorrow's lesson.

Lab Report Rubric

Experiment Design Planning Sheet

Closure

5 minutes

The exit ticket or deliverable for the day is a post it note on my reflective chart in response to these prompts:

My AHA moment...

I am still thinking about...

My learning stopped when...

This chart is posted at the front of the room, and gives me a quick reference into student thinking and attitudes in the classroom. During the beginning weeks of the school-year, I save the post-its and give them back to the students to use as a reference for writing their weekly blogs.